Comparative analysis of surgically treated degenerative cervical and lumbar spine diseases using multiple clinical aging indices

Background: The prevalence of degenerative spine diseases has continued to rise with the aging of the global population. Despite the availability of various aging indices, limited studies have comprehensively investigated degenerative spine diseases from the perspective of aging. This study aimed to evaluate degenerative cervical and lumbar diseases surgically treated using multiple clinical aging indices and elucidate the characteristics of each condition through comparative analysis. Methods: Clinical data of consecutive patients aged ≥ 65 years who underwent surgery for degenerative cervical and lumbar diseases were retrospectively collected. Frailty was assessed using the 11-point modified frailty index. Locomotive syndrome stage was determined based on the 25-Question Geriatric Locomotive Function Scale. Functional decline was assessed according to the Kihon Checklist. Polypharmacy was defined based on a cutoff of six drugs. A total of 19 categories were considered potentially inappropriate medications. Results: Among the included patients, 313 and 103 had degenerative lumbar (L group) and degenerative cervical (C group) diseases, respectively. The C group had significantly lower serum albumin levels (p = 0.03), a significantly higher frequency of functional decline in both physical function (p = 0.02) and activities of daily living (p = 0.046), and significantly more advanced frailty (p = 0.004) than the L group. Among potentially inappropriate medications, the frequency of diuretic use was significantly higher in the C group than in the L group (p = 0.04). Longitudinal observations showed significant postoperative improvements in locomotive syndrome stages in the L group but not the C group. Cross-sectional observations revealed no significant differences in locomotive syndrome stage distributions between both the groups before surgery (p = 0.402); however, the C group exhibited significantly more advanced locomotive syndrome stages than the L group at 6 months (p < 0.001) and 1 year after surgery (p < 0.001). Conclusions: Across various indices of aging, patients with degenerative cervical spine disease showed more significant progression than those with lumbar spine disease. Thorough understanding of these characteristics is essential when managing degenerative spine diseases, particularly in the selection of effective treatment approaches for the increasingly aging society in the future.